The invention relates to an infant stroller, and particularly to an improved folding frame for an infant stroller.
Infant strollers are generally made for holding a single seat. Some of the strollers may be converted to support a dual seat. U.S. Pat. No. D418,780 discloses an example in which a left seat and a right seat are arranged in a juxtaposed manner. There is a handle section equipped with a brake lever to facilitate maneuvering of the stroller. This type of stroller basically is not foldable. It takes a lot of space for transportation and storing, thus is not suitable for every family.
U.S. Pat. No. 5,263,730 proposes a dual seat stroller which has a front seat and a rear seat. Such type of stroller has relatively large wheels to allow the stroller to move on an uneven surface. It is also not foldable and takes a large amount of space for storage and transportation.
To overcome the non-foldable problem of dual-seat strollers, there is a need to provide foldable frames. In general, a stroller frame may be extended to hold a front seat and a rear seat. The extended frame includes at least a handle bracket, armrests, front wheel brackets, rear wheel brackets and a seat bracket. The handle bracket is substantially formed in an inverse xe2x80x9cUxe2x80x9d shape, and is located at the rear end of the infant stroller in an upright or inclined manner. The armrests are horizontally located on two sides of the infant stroller frame with rear ends thereof pivotally engaging with the handle bracket. The armrests may be pivotally turned and moved towards the handle bracket when the frame is folding.
Each front wheel bracket has an upper end pivotally engaging with the front end of the armrest. Each rear wheel bracket is located on one side of the infant stroller in an inclined manner, and has an upper end pivotally engaging with the front end of the armrest (adjacent to the upper end of the front wheel bracket), and a lower end pivotally engaging with a rear wheel through a wheel anchor block. Because the pivotal axes on the upper ends of the front wheel bracket and the rear wheel bracket are spaced close to each other, the front wheel bracket and the rear wheel bracket may be pivotally turned and moved closely toward each other when the frame is folded. As a result, space for transportation and storage can be saved.
Preliminary tests have shown that such infant strollers present difficulties in properly positioning supporting rods for the front seat. It could produce interference when the frame is folding and result in incomplete folding. One possible approach to resolve this issue is to make the supporting rods extendable. However commonly used extendable rods have exposed screws and slots, and are prone to incur scratching or cause injury to people during operation. The construction is also unsightly and does not have much appeal.
In view of aforesaid findings, the primary object of the invention is to provide a foldable frame for an infant stroller. Another object of the invention is to provide an improved extendable rod for the frame of the infant stroller.
The improved extendable rod of the invention includes an inner rod and an outer rod. The outer rod has a longitudinal trough to house the inner rod and allows the inner rod to slide reciprocally therein. For installation, the inner rod is inserted into the longitudinal trough of the outer rod, then the upper end axis of the inner rod is pivotally engaged with one armrest, and the lower end axis of the outer rod is pivotally engaged with the seat bracket. The armrest and seat bracket form a restrictive linkage to prevent the outer rod of the extendable rod from separating from the seat bracket.
According to an embodiment of the invention, the extendable rod may be extended or retracted based on continuous changes of the relative position of the armrest and seat bracket. The extendable rod also does not have exposed slots or screws during the extension or retraction process. It is safer to use and looks more attractive.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. The drawings are only to serve for reference and illustrative purpose, and are not intended to limit the scope of the invention.